Display panel and electronic device including the same

ABSTRACT

A display panel includes a base substrate including a front surface and a rear surface and having first and second holes, and a pixel layer on the base substrate. A display area is defined in the front surface. The first hole overlaps with the display area and penetrates the front and rear surfaces. The second hole overlaps with the display area, is adjacent to the first hole, and is recessed from the front surface. The base substrate includes a first base layer including the rear surface, a first barrier layer on the first base layer and including first inorganic films having a first refractive index, and second inorganic films having a second refractive index, a second base layer on the first barrier layer, and a second barrier layer on the second base layer and including the front surface. The first and second inorganic films are alternately stacked.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/592,625, filed on Oct. 3, 2019, which is a continuation of U.S.patent application Ser. No. 16/022,420, filed on Jun. 28, 2018, now U.S.Pat. No. 10,454,067, which claims priority to and the benefit of KoreanPatent Application No. 10-2017-0153370, filed on Nov. 16, 2017 in theKorean Intellectual Property Office, the entire content of each of whichis herein incorporated by reference.

BACKGROUND 1. Field

Aspects of embodiments of the present invention relate to a displaypanel and an electronic device including the same.

2. Description of the Related Art

Display devices may display images, and an organic light emittingdisplay device is spotlighted as a next-generation display device. Theorganic light emitting display device has high-quality characteristics,such as low power consumption, high brightness, and a high responsespeed.

The organic light emitting display device may include an organic lightemitting element. However, the organic light emitting element may beeasily damaged by moisture or oxygen. Thus, external moisture or oxygenshould be stably blocked to improve the life span and reliability of theorganic light emitting display device.

SUMMARY

According to aspects of embodiments of the present invention, a displaypanel having improved reliability and an electronic device including thesame are provided. According to further aspects of embodiments of thepresent invention, a display panel capable of effectively blocking anexternal contaminant and an electronic device including the same areprovided.

According to one or more embodiments of the present invention, a displaypanel includes a base substrate which includes a front surface and arear surface and in which a first hole and a second hole are defined,and a pixel layer on the base substrate. A display area may be definedin the front surface. The first hole may overlap with the display areaand may penetrate the front surface and the rear surface. The secondhole may overlap with the display area, may be adjacent to the firsthole, and may be recessed from the front surface. The base substrate mayinclude a first base layer including the rear surface of the basesubstrate, a first barrier layer on the first base layer and including aplurality of first inorganic films having a first refractive index; anda plurality of second inorganic films having a second refractive index,a second base layer on the first barrier layer, and a second barrierlayer on the second base layer and including the front surface of thebase substrate. The second inorganic films and the first inorganic filmsmay be alternately stacked. The second hole may be defined in the secondbase layer and the second barrier layer.

In an embodiment, an uppermost film of the first barrier layer may beone of the first inorganic films, and a lowermost film of the firstbarrier layer may be one of the second inorganic films. The secondrefractive index may be higher than the first refractive index.

In an embodiment, at least two or more of the first inorganic films mayhave different thicknesses from each other, and at least two or more ofthe second inorganic films may have different thicknesses from eachother.

In an embodiment, the first inorganic films and the second inorganicfilms may have different thicknesses from each other.

In an embodiment, a thickness of the first barrier layer may be from 550nm to 600 nm.

In an embodiment, the first inorganic films may include silicon oxide(SiOx), and the second inorganic films may include silicon nitride(SiNx).

In an embodiment, the second hole may include a first sub-holepenetrating the second barrier layer, and a second sub-hole overlappingwith the first sub-hole and defined in the second base layer.

In an embodiment, a width of the second sub-hole defined in the secondbase layer may be greater than a width of the first sub-hole penetratingthe second barrier layer.

In an embodiment, the pixel layer may include a cover layer which isdisposed on the second barrier layer and in which a third sub-holeoverlapping with the second hole is defined.

In an embodiment, a width of the third sub-hole of the cover layer maybe equal to or less than a width of the first sub-hole of the secondbarrier layer.

In an embodiment, the pixel layer may include a thin film element layeron the base substrate and including a thin film transistor, and adisplay element layer on the base substrate and including an organiclight emitting element connected to the thin film transistor.

In an embodiment, the display area may include a hole area overlappingwith the first hole, a peripheral area surrounding the hole area andoverlapping with the second hole, and a pixel area surrounding theperipheral area and overlapping with the organic light emitting element.The organic light emitting element may not overlap with the peripheralarea.

In an embodiment, the pixel layer may not overlap with the hole area.

In an embodiment, a third hole may further be defined in the basesubstrate. The third hole may overlap with the display area and may becloser to the second hole than to the first hole, when viewed in a planview. The third hole may be recessed from the front surface of the basesubstrate.

In an embodiment, the third hole may include a third sub-holepenetrating the second barrier layer, and a fourth sub-hole overlappingwith the third sub-hole and defined in the second base layer.

In an embodiment, a width of the fourth sub-hole defined in the secondbase layer may be greater than a width of the third sub-hole penetratingthe second barrier layer.

In an embodiment, the first base layer and the second base layer mayinclude an organic material.

According to one or more embodiments of the present invention, anelectronic device may include: a display panel including a basesubstrate which includes a front surface and a rear surface and in whicha first hole and a second hole are defined, and an electronic modulereceived in the first hole and electrically connected to the displaypanel. A display area and a non-display area adjacent to the displayarea may be defined in the front surface in a plan view. The first holemay overlap with the display area and may penetrate the front surfaceand the rear surface. The second hole may overlap with the display area,may be adjacent to the first hole, and may be recessed from the frontsurface. The base substrate may include a first base layer including therear surface of the base substrate, a first barrier layer on the firstbase layer and including a plurality of first inorganic films having afirst refractive index, and a plurality of second inorganic films havinga second refractive index, a second base layer on the first barrierlayer, and a second barrier layer on the second base layer and includingthe front surface of the base substrate. The second inorganic films andthe first inorganic films may be alternately stacked. The second holemay be defined in the second base layer and the second barrier layer.

In an embodiment, the electronic module may include at least one of asound output module, a camera module, or a light receiving module.

In an embodiment, the second hole may have a closed loop shapesurrounding the first hole, when viewed in a plan view.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects and features of the present invention willbecome more apparent by describing in further detail some exemplaryembodiments thereof with reference to the accompanying drawings, inwhich:

FIG. 1A is a perspective view illustrating an electronic device,according to an embodiment of the invention;

FIG. 1B is an exploded perspective view illustrating an electronicdevice, according to an embodiment of the invention;

FIG. 1C is a block diagram illustrating an electronic device, accordingto an embodiment of the invention;

FIG. 2 is a cross-sectional view taken along the line I-I′ of FIG. 1B;

FIG. 3A is an enlarged cross-sectional view of a portion of FIG. 2;

FIG. 3B is an enlarged cross-sectional view of a portion of FIG. 3A;

FIG. 4 is a cross-sectional view illustrating a first barrier layer ofFIG. 2, according to an embodiment of the invention;

FIG. 5 is a graph showing characteristics of a laser transmitted througha first barrier layer, according to an embodiment of the invention;

FIG. 6 is a cross-sectional view illustrating a portion of the firstbarrier layer of FIG. 4, according to an embodiment of the invention;

FIGS. 7A to 7D are cross-sectional views illustrating a method ofmanufacturing a display panel, according to an embodiment of theinvention;

FIG. 7E is an image showing a base substrate, according to an embodimentof the invention; and

FIG. 8 is a cross-sectional view illustrating a display panel of anelectronic device, according to another embodiment of the invention.

DETAILED DESCRIPTION

The invention now will be described more fully herein with reference tothe accompanying drawings, in which various embodiments are shown. Thisinvention may, however, be embodied in many different forms, and shouldnot be construed as limited to the embodiments set forth herein. Rather,these embodiments are provided so that this disclosure will be thoroughand complete and will convey the scope of the invention to those skilledin the art. Like reference numerals refer to like elements throughout.

It is to be understood that when an element, such as a layer, region, orsubstrate is referred to as being “on” another element, it may bedirectly on the other element or one or more intervening elements may bepresent. In contrast, the term “directly” means that there are nointervening elements. As used herein, the term “and/or” includes any andall combinations of one or more of the associated listed items. Theterminology used herein is for the purpose of describing particularembodiments and is not intended to be limiting. As used herein, thesingular forms “a,” “an,” and “the” are intended to include the pluralforms, including “at least one,” unless the content clearly indicatesotherwise. “Or” means “and/or.” As used herein, the term “and/or”includes any and all combinations of one or more of the associatedlisted items. It is to be further understood that the terms “comprises”and/or “comprising,” or “includes” and/or “including” when used in thisspecification, specify the presence of stated features, regions,integers, steps, operations, elements, and/or components, but do notpreclude the presence or addition of one or more other features,regions, integers, steps, operations, elements, components, and/orgroups thereof. Spatially relative terms, such as “beneath,” “below,”“lower,” “above,” “upper,” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. It is to beunderstood that the spatially relative terms are intended to encompassdifferent orientations of the device in use or operation in addition tothe orientation depicted in the figures. For example, if the device inthe figures is turned over, elements described as “below” or “beneath”other elements or features would then be oriented “above” the otherelements or features. Thus, the exemplary term “below” can encompassboth an orientation of above and below. The device may be otherwiseoriented (e.g., rotated 90 degrees or at other orientations) and thespatially relative descriptors used herein interpreted accordingly.

It is to be understood that, although the terms “first,” “second,” etc.may be used herein to describe various elements, components, regions,layers, and/or sections, these elements, components, regions, layers,and/or sections should not be limited by these terms. These terms areused to distinguish one element, component, region, layer, or sectionfrom another element, component, region, layer, or section. Thus, a“first” element, component, region, layer, or section discussed belowcould be termed a “second” element, component, region, layer, or sectionwithout departing from the teachings herein. Some exemplary embodimentsare described herein with reference to cross-sectional illustrationsand/or plane illustrations that are idealized exemplary illustrations.In the drawings, the thicknesses of layers and regions may beexaggerated for clarity. Accordingly, variations from the shapes of theillustrations as a result, for example, of manufacturing techniquesand/or tolerances, are to be expected. Thus, exemplary embodimentsshould not be construed as limited to the shapes of regions illustratedherein but are to include deviations in shapes that result, for example,from manufacturing. For example, an etching region illustrated as arectangle will, typically, have rounded or curved features. Thus, theregions illustrated in the figures are schematic in nature and theirshapes are not intended to necessarily illustrate the actual shape of aregion of a device and are not intended to limit the scope of exemplaryembodiments.

FIG. 1A is a perspective view illustrating an electronic device,according to an embodiment of the invention; FIG. 1B is an explodedperspective view illustrating an electronic device, according to anembodiment of the invention; and FIG. 1C is a block diagram illustratingan electronic device, according to an embodiment of the invention.

According to an embodiment of the invention, an electronic device EDDmay be activated by an electrical signal. The electronic device EDD maybe realized as any of various embodiments. For example, the electronicdevice EDD may be realized as a tablet, a notebook computer, a personalcomputer, a smart television, or a smartphone. In the presentembodiment, a smartphone is illustrated as an example of the electronicdevice EDD.

Referring to FIGS. 1A, 1B, and 1C, the electronic device EDD may providea display surface displaying an image IM at a front surface thereof. Thedisplay surface may be parallel to a plane defined by a first directionDR1 and a second direction DR2.

A normal direction of the display surface may be indicated by a thirddirection DR3. The third direction DR3 may also indicate a thicknessdirection of the electronic device EDD. A front surface and a rearsurface of each of members may be distinguished by the third directionDR3. However, the first to third directions DR1, DR2, and DR3 may berelative concepts and may be varied to be other directions.

According to FIG. 1A, the electronic device EDD may display the image IMthrough a transmission area TA. In FIG. 1A, an internet search box isillustrated as an example of the image IM. In an embodiment, thetransmission area TA may have a quadrilateral shape parallel to thefirst and second directions DR1 and DR2. However, embodiments of theinvention are not limited thereto, and the shape of the transmissionarea TA may be variously modified.

A bezel area BZA may be adjacent to the transmission area TA. In anembodiment, the bezel area BZA may surround the transmission area TA.However, embodiments of the invention are not limited thereto. In otherembodiments, the bezel area BZA may be adjacent to one or more sides ofthe transmission area TA or may be omitted. The electronic device EDDmay include any of various embodiments but may not be limited to aspecific embodiment.

According to FIG. 1B, in an embodiment, the electronic device EDD mayinclude a display panel 100, a window member 200, a housing member 300,and an electronic module 400.

As illustrated in FIG. 1C, in an embodiment, the electronic device EDDmay further include a display module DM, a first electronic module EM1,a second electronic module EM2, and a power supply module PM. Some ofcomponents illustrated in FIG. 1C are not shown in the electronic deviceEDD illustrated in FIG. 1B for the purpose of ease and convenience indescription and illustration.

In an embodiment, the display module DM may include the display panel100 and an input sensing unit TSU. The display panel 100 may generatethe image IM. The input sensing unit TSU may sense an input of a usersupplied from the outside. The input of a user may include at least oneof various external inputs, such as any of a part (e.g., a finger) of abody of a user, light, heat, and pressure. In an embodiment, the inputsensing unit TSU may further include a touch sensor.

Referring again to FIG. 1B, a display area DA and a non-display area NDAmay be defined in the display panel 100. The image IM may be generatedthrough the display area DA. A plurality of pixels for generating theimage IM may be disposed in the display area DA. This will be describedlater in further detail.

The non-display area NDA may be adjacent to the display area DA. In anembodiment, the non-display area NDA may surround the display area DA. Adriving circuit and/or driving lines for driving the display area DA maybe disposed in the non-display area NDA.

In an embodiment, although not shown in the drawings, the non-displayarea NDA of the display panel 100 may be partially curved. Thus, aportion of the non-display area NDA may face a front surface of theelectronic device EDD, and another portion of the non-display area NDAmay face a rear surface of the electronic device EDD. Alternatively, thenon-display area NDA may be omitted in the display panel 100 accordingto another embodiment of the invention.

According to an embodiment of the invention, the display panel 100 mayinclude a receiving portion OA overlapping with the display area DA. Thereceiving portion OA may include a space in which the electronic module400 is disposed. The receiving portion OA may include a first hole MHand a second hole BR.

The first hole MH may penetrate the display panel 100. In an embodiment,the first hole MH may have a cylindrical shape having a height in thethird direction DR3. The first hole MH may receive the electronic module400. According to an embodiment, the display panel 100 includes thefirst hole MH, and a thin display device or electronic device may berealized.

The second hole BR may be disposed adjacent to the first hole MH. Thesecond hole BR may be formed to be recessed from a front surface of thedisplay panel 100. The second hole BR may have a closed loop shapesurrounding the first hole MH in a portion of the display panel 100 whenviewed in a plan view. In the present embodiment, the second hole BR mayhave a ring shape surrounding the first hole MH in a plan view.

According to an embodiment of the invention, the first hole MH may be athrough-hole which penetrates the front surface and a rear surface ofthe display panel 100. Unlike the first hole MH, the second hole BR maynot completely penetrate the display panel 100 but may penetrate only aportion of the display panel 100 in the third direction DR3. As aresult, the second hole BR may not be a through-hole but may have aconcave or recessed shape. The first hole MH and the second hole BR willbe described later in more detail.

The window member 200 may provide the front surface of the electronicdevice EDD. The window member 200 may be disposed on the front surfaceof the display panel 100 to protect the display panel 100. In anembodiment, the window member 200 may include a glass substrate, asapphire substrate, or a plastic film, for example. The window member200 may have a single-layered or multi-layered structure. For example,the window member 200 may have a stack structure including a pluralityof plastic films coupled to each other by an adhesive or may have astack structure which includes a glass substrate and a plastic filmcoupled to each other by an adhesive.

The window member 200 may be divided into the transmission area TA andthe bezel area BZA. The transmission area TA may correspond to thedisplay area DA. For example, the transmission area TA may overlap witha whole or at least a portion of the display area DA. The image IMdisplayed on the display area DA of the display panel 100 may be visibleto the outside through the transmission area TA.

The bezel area BZA may define the shape of the transmission area TA. Inan embodiment, the bezel area BZA may be adjacent to the transmissionarea TA and may surround the transmission area TA in a plan view. Thebezel area BZA may have a color (e.g., a predetermined color). The bezelarea BZA may cover the non-display area NDA of the display panel 100 toprevent or substantially prevent the non-display area NDA from beingvisible to the outside. However, embodiments of the invention are notlimited thereto. In another embodiment of the invention, the bezel areaBZA may be omitted in the window member 200.

The housing member 300 may be coupled to the window member 200. Thehousing member 300 may provide the rear surface of the electronic deviceEDD. The housing member 300 may be coupled to the window member 200 todefine an inner space, and the display panel 100, the electronic module400 and various components may be received in the inner space. Thehousing member 300 may be formed of a material having relatively highrigidity. For example, the housing member 300 may include a plurality offrames and/or plates, which may be formed of glass, plastic, and/or ametal. The housing member 300 may stably protect the components of theelectronic device EDD received in the inner space from an externalimpact.

The electronic module 400 may include at least one of various functionalmodules for operating the electronic device EDD.

Referring to FIG. 1C, the electronic module 400 may include at least oneof components of the first and second electronic modules EM1 and EM2.

In an embodiment, the first electronic module EM1 may be mounteddirectly on a motherboard electrically connected to the display moduleDM. In another embodiment, the first electronic module EM1 may bemounted on an additional board so as to be electrically connected to themotherboard through a connector (not shown).

In an embodiment, the first electronic module EM1 may include a controlmodule CM, a wireless communication module 510, an image input module520, a sound input module 530, a memory 540, and an external interface550. In an embodiment, one or more of the components (e.g., the modules)may not be mounted on the motherboard but may be electrically connectedto the motherboard through a flexible circuit board.

The control module CM may control overall operations of the electronicdevice EDD. The control module CM may include a microprocessor. Forexample, the control module CM may activate or deactivate the displaymodule DM. In an embodiment, the control module CM may control one ormore other modules (e.g., the image input module 520, the sound inputmodule 530, etc.) on the basis of a touch signal received from thedisplay module DM.

The wireless communication module 510 may transmit/receive a wirelesssignal to/from one or more other terminals by using Bluetooth or Wi-Fi,for example. The wireless communication module 510 may transmit/receivea voice signal by using a general communication line. The wirelesscommunication module 510 may include a transmitter 512 which modulates asignal to be transmitted and transmits the modulated signal, and areceiver 511 which demodulates a received signal.

The image input module 520 may process an image signal to convert theimage signal into image data for displaying an image in the displaymodule DM. The sound input module 530 may receive an external soundsignal through a microphone in a recording mode or a voice recognitionmode and may convert the received sound signal into electrical sounddata.

In an embodiment, the external interface 550 may be connected to andinterface with an external charger, a cable/wireless data port, or acard socket (e.g., a memory card or a SIM/UIM card).

In an embodiment, the second electronic module EM2 may include a soundoutput module 560, a light emitting module 570, a light receiving module580, and a camera module 590. The components of the second electronicmodule EM2 may be mounted directly on the motherboard or may be mountedon an additional board so as to be electrically connected to the displaymodule DM and/or the first electronic module EM1 through a connector(not shown).

The sound output module 560 may convert sound data received from thewireless communication module 510 or sound data stored in the memory 540and may output the converted sound data to the outside.

The light emitting module 570 may generate light and may output thegenerated light. The light emitting module 570 may output infraredlight. In an embodiment, the light emitting module 570 may include alight emitting diode (LED) element. The light receiving module 580 maysense infrared light. The light receiving module 580 may be activatedwhen sensing the infrared light of a level (e.g. a predetermined level)or more. In an embodiment, the light receiving module 580 may include aCMOS image sensor. After the infrared light generated in the lightemitting module 570 is outputted, the infrared light may be reflected byan external object (e.g., a finger or a face of a user) and thereflected infrared light may be incident to the light receiving module580. The camera module 590 may acquire an external image.

The electronic module 400 illustrated in FIG. 1B may be one of thecomponents of the second electronic module EM2. In this case, the othercomponents of the first and second electronic modules EM1 and EM2 may bedisposed at other positions. However, embodiments of the invention arenot limited thereto. In other embodiments, the electronic module 400 mayinclude one or more of the modules of the first and second electronicmodules EM1 and EM2.

The power supply module PM may supply power for overall operations ofthe electronic device EDD. The power supply module PM may include abattery module.

FIG. 2 is a cross-sectional view taken along the line I-I′ of FIG. 1B;FIG. 3A is an enlarged cross-sectional view of a portion of FIG. 2; andFIG. 3B is an enlarged cross-sectional view of a portion of FIG. 3A.

According to FIG. 2, the display area DA and the non-display area NDAare illustrated. According to an embodiment, the display area DA mayinclude a hole area HA in which the first hole MH is formed, aperipheral area BA which surrounds the hole area HA and in which thesecond hole BR is formed, and a pixel area PA which surrounds theperipheral area BA. An organic light emitting element ED may be disposedon a thin film element layer 20 to overlap with the pixel area PA. Thehole area HA may not overlap with a base substrate 10, the thin filmelement layer 20, and a display element layer 30, and the peripheralarea BA may not overlap with the organic light emitting element ED.

Referring to FIG. 2, the display panel 100 may include the basesubstrate 10, the thin film element layer 20, and the display elementlayer 30.

The thin film element layer 20 and the display element layer 30 may beincluded in a pixel layer. The base substrate 10, the thin film elementlayer 20, and the display element layer 30 may be stacked in the thirddirection DR3.

The base substrate 10 may include a first base layer 11, a first barrierlayer 12, a second base layer 13, and a second barrier layer 14.

The first base layer 11 may correspond to a lower layer of the basesubstrate 10. A rear surface of the first base layer 11 may define arear surface of the base substrate 10.

In an embodiment, the first base layer 11 may be an insulating layerincluding an organic material. In an embodiment, the first base layer 11may include a flexible plastic. For example, the first base layer 11 mayinclude polyimide (PI), polyethylene naphthalate (PEN), polyethyleneterephthalate (PET), polyarylate, polycarbonate (PC), polyetherimide(PEI), or polyether sulfone (PES).

In an embodiment, the first barrier layer 12 may include an inorganicmaterial and may be disposed on the first base layer 11. In other words,the first barrier layer 12 may be an insulating layer including theinorganic material. For example, the first barrier layer 12 may includesilicon oxide (SiOx), silicon nitride (SiNx), or amorphous silicon (Si).

The second base layer 13 may be disposed on the first barrier layer 12and may be an insulating layer including an organic material. In anembodiment, the second base layer 13 may include the same material asthe first base layer 11.

In an embodiment, the second barrier layer 14 may include an inorganicmaterial, and a front surface of the second barrier layer 14 may definea front surface of the base substrate 10.

The first and second base layers 11 and 13 and the first and secondbarrier layers 12 and 14 may be alternately stacked. In particular, thefirst barrier layer 12 and the second barrier layer 14 may blockexternal moisture or oxygen passing through the first base layer 11 andthe second base layer 13, respectively.

According to an embodiment of the invention, the first hole MH maypenetrate the first base layer 11, the first barrier layer 12, thesecond base layer 13, and the second barrier layer 14. The second holeBR may surround the first hole MH and may be formed in the second baselayer 13 and the second barrier layer 14. The second hole BR is notformed in the first base layer 11 and the first barrier layer 12.

If the second hole BR is formed in the first barrier layer 12 and aportion of the first base layer 11, moisture or oxygen permeatingthrough the rear surface of the first base layer 11 may be transferredto the thin film element layer 20 or the display element layer 30through the second hole BR. The external moisture or oxygen may beblocked by the first and second barrier layers 12 and 14 including theinorganic material. However, if the second hole BR is defined in boththe first and second barrier layers 12 and 14, the moisture or oxygenpermeating through the rear surface of the first base layer 11 may beprovided to the pixel area PA through the second hole BR.

However, the second hole BR according to the invention surrounds thefirst hole MH and is formed in the second base layer 13 and the secondbarrier layer 14. In other words, the second hole BR according to theinvention is not formed in the first base layer 11 and the first barrierlayer 12.

In an embodiment, external laser light may be used to form the firsthole MH and the second hole BR. In this case, the first hole MH may beformed by laser light of a first wavelength band, and the second hole BRmay be formed by laser light of a second wavelength band. The laserlight of the first wavelength band may completely recess a portion ofthe base substrate 10 to form the first hole MH. The laser light of thesecond wavelength band may recess a portion of the second barrier layer14 and a portion of the second base layer 13 to form the second hole BR.

According to an embodiment of the invention, the first barrier layer 12may include a plurality of first inorganic films having a firstrefractive index and a plurality of second inorganic films having asecond refractive index. The first inorganic films and the secondinorganic films may be alternately stacked. The first refractive indexmay be different from the second refractive index.

In an embodiment, when the laser light of the second wavelength bandused to form the second hole BR is incident on the first barrier layer12, the first barrier layer 12 may reflect the laser light of the secondwavelength band. Thus, the second hole BR may not be formed in the firstbarrier layer 12 and the first base layer 11 by the laser light of thesecond wavelength band. As a result, moisture or oxygen permeatingthrough the rear surface of the first base layer may be blocked by thefirst barrier layer 12. The structure of the first barrier layer 12 willbe described later in more detail.

The thin film element layer 20 may be disposed on the base substrate 10.The thin film element layer 20 may include a plurality of insulatinglayers and a thin film transistor TR. Each of the insulating layers mayinclude an inorganic material and/or an organic material. The insulatinglayers may include first to third insulating layers 21, 22, and 23.

The thin film transistor TR may include a semiconductor pattern SL, acontrol electrode CE, an input electrode IE, and an output electrode OE.The thin film transistor TR may control movement of charges in thesemiconductor pattern SL by the control electrode CE to output anelectrical signal, inputted from the input electrode IE, through theoutput electrode OE.

The first insulating layer 21 may be disposed between the semiconductorpattern SL and the control electrode CE. In the present embodiment, thecontrol electrode CE is disposed on the semiconductor pattern SL.However, embodiments of the invention are not limited thereto. Inanother embodiment, the thin film transistor TR may include thesemiconductor pattern SL disposed on the control electrode CE.

The second insulating layer 22 may be disposed between the controlelectrode CE and the input and output electrodes IE and OE. The secondinsulating layer 22 may cover the control electrode CE, and the inputand output electrodes IE and OE may be disposed on the second insulatinglayer 22. The input electrode IE and the output electrode OE maypenetrate the first and second insulating layers 21 and 22 so as to beconnected to portions of the semiconductor pattern SL, respectively.However, embodiments of the invention are not limited thereto. Inanother embodiment, the input electrode IE and the output electrode OEmay be connected directly to the semiconductor pattern SL.

The third insulating layer 23 may be disposed on the second insulatinglayer 22. The third insulating layer 23 may cover the thin filmtransistor TR. The third insulating layer 23 may electrically insulatethe thin film transistor TR from the display element layer 30.

The display element layer 30 may include the organic light emittingelement ED and a plurality of insulating layers. The insulating layersof the display element layer 30 may include a fourth insulating layer 31and an encapsulation member TE.

The fourth insulating layer 31 may be disposed on the third insulatinglayer 23. A plurality of openings may be defined in the fourthinsulating layer 31. The organic light emitting element ED may beprovided in each of the openings.

The organic light emitting element ED may overlap with the pixel areaPA. The organic light emitting element ED may include a first electrodeE1, a second electrode E2, an emission layer EL, and a charge controllayer OL. The first electrode E1 may be disposed on the thin filmelement layer 20. The first electrode E1 may penetrate the thirdinsulating layer 23 so as to be electrically connected to the thin filmtransistor TR (e.g., the output electrode OE of the thin film transistorTR). The first electrode E1 may be provided in plurality. At least aportion of each of the first electrodes E1 may be exposed by each of theopenings.

The second electrode E2 may be disposed on the first electrode E1. Thesecond electrode E2 may have a single body shape overlapping with theplurality of first electrodes E1 and the fourth insulating layer 31.When the organic light emitting element ED is provided in plurality, thesecond electrode E2 of the organic light emitting elements ED may have acommon voltage. Thus, an additional patterning process for forming thesecond electrode E2 may be omitted. However, embodiments of theinvention are not limited thereto. In another embodiment, the secondelectrode E2 may be provided in plurality, and the plurality of secondelectrodes E2 may correspond to the plurality of openings, respectively.

The emission layer EL may be disposed between the first electrode E1 andthe second electrode E2. The emission layer EL may be provided inplurality, and the plurality of emission layers EL may be disposed inthe plurality of openings, respectively. The organic light emittingelement ED may activate the emission layer EL by a potential differencebetween the first and second electrodes E1 and E2 to generate light.

The charge control layer OL may be disposed between the first electrodeE1 and the second electrode E2. The charge control layer OL may bedisposed adjacent to the emission layer EL. In the present embodiment,the charge control layer OL is disposed between the emission layer ELand the second electrode E2. However, embodiments of the invention arenot limited thereto. In other embodiments, the charge control layer OLmay be disposed between the emission layer EL and the first electrodeE1, or the charge control layer OL may include a plurality of layersstacked in the third direction DR3 with the emission layer EL interposedtherebetween.

In an embodiment, the charge control layer OL may have a single bodyshape overlapping with substantially an entire top surface of the basesubstrate 10, without an additional patterning process. The chargecontrol layer OL may be disposed in the openings and may also bedisposed on a top surface of the fourth insulating layer 31.

The encapsulation member TE may be disposed on the organic lightemitting element ED. The encapsulation member TE may include aninorganic layer and/or an organic layer. In the present embodiment, theencapsulation member TE may include a first inorganic layer 32, anorganic layer 33, and a second inorganic layer 34.

Each of the first and second inorganic layers 32 and 34 may include aninorganic material. For example, each of the first and second inorganiclayers 32 and 34 may include at least one of aluminum oxide, siliconoxide, silicon nitride, silicon oxynitride, silicon carbide, titaniumoxide, zirconium oxide, or zinc oxide. The first inorganic layer 32 andthe second inorganic layer 34 may include the same material or differentmaterials from each other.

The organic layer 33 may be disposed between the first inorganic layer32 and the second inorganic layer 34. The organic layer 33 may includean organic material. For example, the organic layer 33 may include atleast one of epoxy, polyimide (PI), polyethylene terephthalate (PET),polycarbonate (PC), polyethylene (PE), or polyacrylate.

In an embodiment, each of the first and second inorganic layers 32 and34 may have a single body shape disposed on substantially an entiresurface of the display panel 100. Each of the first and second inorganiclayers 32 and 34 may partially overlap with the organic layer 33. Thus,the first inorganic layer 32 and the second inorganic layer 34 may bespaced apart from each other in the third direction DR3 with the organiclayer 33 interposed therebetween in an area and may be in direct contactwith each other in the third direction DR3 in another area.

In an embodiment, the display panel 100 may further include a damportion DMP. The dam portion DMP may extend in the non-display area NDAalong an edge of the display area DA (see FIG. 2). The dam portion DMPmay surround the display area DA.

In an embodiment, the dam portion DMP may include a first dam DM1 and asecond dam DM2. In an embodiment, the first dam DM1 may include the samematerial as the third insulating layer 23, and the first dam DM1 may beformed concurrently (e.g., simultaneously) with the third insulatinglayer 23 and may be disposed on the same layer as the third insulatinglayer 23.

The second dam DM2 may be stacked on the first dam DM1. In anembodiment, the second dam DM2 may include the same material as thefourth insulating layer 31, and the second dam DM2 may be formedconcurrently (e.g., simultaneously) with the fourth insulating layer 31and may be disposed on the same layer as the fourth insulating layer 31.However, embodiments of the invention are not limited thereto. Inanother embodiment, the dam portion DMP may have a single-layeredstructure.

The dam portion DMP may define an area in which a liquid organicmaterial is spread in a process of forming the organic layer 33. In anembodiment, a liquid organic material may be provided onto the firstinorganic layer 32 by an inkjet method to form the organic layer 33. Atthis time, the dam portion DMP may define a boundary of an area in whichthe liquid organic material is disposed, thereby preventing orsubstantially preventing the liquid organic material from overflowing tothe outside.

Herein, the area in which the first and second holes MH and BR aredefined will be described in more detail with reference to FIGS. 3A and3B. In FIG. 3B, the first and second inorganic layers 32 and 34 are notshown for the purpose of ease and convenience in description andillustration. The first hole MH may penetrate the display panel 100along the third direction DR3. Since the first hole MH is defined in thedisplay area DA, the first hole MH may penetrate some of the layersconstituting the display area DA as well as the base substrate 10.

In more detail, the first hole MH may penetrate the base substrate 10.An inner surface 10-EG_H of the first hole MH may be defined by ends ofa plurality of layers. An end 11-E of the first base layer 11, an end12-E of the first barrier layer 12, an end 13-E of the second base layer13, and an end 14-E of the second barrier layer 14 may be defined at thefirst base layer 11, the first barrier layer 12, the second base layer13, and the second barrier layer 14, respectively.

In addition, the first hole MH may also penetrate at least one or moreof the layers constituting the display area DA. For example, the firsthole MH may penetrate the first insulating layer 21, the charge controllayer OL, the first inorganic layer 32, and the second inorganic layer34. Thus, an end 21-E of the first insulating layer 21, an end OL-E ofthe charge control layer OL, an end 32-E of the first inorganic layer32, and an end 34-E of the second inorganic layer 34 may be defined atthe first insulating layer 21, the charge control layer OL, the firstinorganic layer 32, and the second inorganic layer 34, respectively.

In the present embodiment, the end 11-E of the first base layer 11, theend 12-E of the first barrier layer 12, the end 13-E of the second baselayer 13, the end 14-E of the second barrier layer 14, the end 21-E ofthe first insulating layer 21, the end OL-E of the charge control layerOL, the end 32-E of the first inorganic layer 32, and the end 34-E ofthe second inorganic layer 34 may be aligned with each other in thethird direction DR3. Thus, the first hole MH may have the cylindricalshape having the height in the third direction DR3. However, embodimentsof the invention are not limited thereto. In another embodiment, atleast one of the ends of the layers defining the first hole MH may notbe aligned with at least another of the ends. In the present embodiment,the first hole MH has the cylindrical shape. However, embodiments of theinvention are not limited thereto. In other embodiments, the first holeMH may have a quadrilateral pillar shape or a polygonal pillar shape,for example.

The second hole BR may be defined adjacent to the first hole MH. Thesecond hole BR may be spaced apart from the first hole MH in the firstdirection DR1. The second hole BR may be recessed from the front surfaceof the base substrate 10 in the third direction DR3. The second hole BRmay penetrate the front surface of the base substrate 10 but may notpenetrate the rear surface of the base substrate 10.

The second hole BR may be formed by removing a portion of the basesubstrate 10. For example, the second hole BR may be formed by removinga portion of the second base layer 13 and a portion of the secondbarrier layer 14.

According to an embodiment of the invention, the second hole BR mayinclude an inner surface which is defined in the base substrate 10 andhas an undercut shape. The second hole BR may include a first sub-hole14-OP penetrating the second barrier layer 14, and a second sub-hole13-OP overlapping with the first sub-hole 14-OP and defined in thesecond base layer 13. The first sub-hole 14-OP and the second sub-hole13-OP may form the undercut shape at the inner surface of the secondhole BR.

The second sub-hole 13-OP defined in the second base layer 13 and thefirst sub-hole 14-OP penetrating the second barrier layer 14 may bestacked in a direction from the first barrier layer 12 toward the frontsurface of the base substrate 10. The first sub-hole 14-OP penetratingthe second barrier layer 14 and the second sub-hole 13-OP defined in thesecond base layer 13 may form the undercut shape.

In an embodiment, an inner surface of the first sub-hole 14-OPpenetrating the second barrier layer 14 may be aligned with an innersurface of the second sub-hole 13-OP defined in the second base layer 13or may laterally protrude from the inner surface of the second sub-hole13-OP defined in the second base layer 13. When the inner surface of thefirst sub-hole 14-OP laterally protrudes from the inner surface of thesecond sub-hole 13-OP, the undercut shape may be formed between thefirst sub-hole 14-OP penetrating the second barrier layer 14 and thesecond sub-hole 13-OP defined in the second base layer 13.

In an embodiment, the second sub-hole 13-OP defined in the second baselayer 13 may have different planar areas along the third direction DR3.In an embodiment, a width of the second sub-hole 13-OP in the firstdirection DR1 at a rear surface of the second base layer 13 may be lessthan a width of the second sub-hole 13-OP in the first direction DR1 ata front surface of the second base layer 13. In an embodiment, thesecond sub-hole 13-OP defined in the second base layer 13 may have atruncated cone shape. However, embodiments of the invention are notlimited thereto. In other embodiments, the second sub-hole 13-OP definedin the second base layer 13 may have a truncated pyramid shape or atruncated elliptical cone shape, which corresponds to the shape of thesecond hole BR in a plan view.

In an embodiment, the thin film element layer 20 and the display elementlayer 30 may partially overlap with the second hole BR. For example, thefirst insulating layer 21 may extend adjacent to the second hole BR andmay partially overlap with the second hole BR. The first insulatinglayer 21 may cover at least a portion of the second hole BR. The firstinsulating layer 21 may include a third sub-hole 21-OP defined in anarea corresponding to the second hole BR. The third sub-hole 21-OP ofthe first insulating layer 21 may overlap with the second hole BR.

In the present embodiment, a width R3 in the first direction DR1 of thethird sub-hole 21-OP of the first insulating layer 21 may be equal to orless than a width R1 in the first direction DR1 of the first sub-hole14-OP penetrating the second barrier layer 14. An inner surface of thethird sub-hole 21-OP of the first insulating layer 21 may be alignedwith the inner surface of the first sub-hole 14-OP penetrating thesecond barrier layer 14 or may laterally protrude from the inner surfaceof the first sub-hole 14-OP penetrating the second barrier layer 14.When the inner surface of the third sub-hole 21-OP laterally protrudesfrom the inner surface of the first sub-hole 14-OP, an undercut shapemay be formed between the third sub-hole 21-OP of the first insulatinglayer 21 and the first sub-hole 14-OP penetrating the second barrierlayer 14.

The charge control layer OL may extend to an area adjacent to the firsthole MH and an area adjacent to the second hole BR. The charge controllayer OL may not overlap with at least a portion of the second hole BR.Thus, the charge control layer OL may have a cut end adjacent to thesecond hole BR.

The first inorganic layer 32 and the second inorganic layer 34 mayextend to the area in which the second hole BR is disposed. In anembodiment, the first and second inorganic layers 32 and 34 may bedisposed in an area adjacent to the second hole BR and may extend alongthe inner surface of the second hole BR. Thus, an inside of the secondhole BR may be covered by the first inorganic layer 32 and the secondinorganic layer 34.

According to an embodiment of the invention, the charge control layer OLmay have the cut end adjacent to the second hole BR and may not overlapwith at least a portion of the second hole BR. The cut end, adjacent tothe second hole BR, of the charge control layer OL is covered by thefirst inorganic layer 32 and the second inorganic layer 34.

As illustrated in FIGS. 3A and 3B, the base substrate 10, the thin filmelement layer 20, and the display element layer 30 may have cut ends inthe area adjacent to the first hole MH. The cut ends are exposed throughthe first hole MH. Moisture or oxygen outside the display panel 100 maybe provided to the base substrate 10, the thin film element layer 20 andthe display element layer 30 through the ends exposed by the first holeMH.

However, according to embodiments of the invention, since the secondhole BR is defined adjacent to the first hole MH, the moisture or oxygenprovided from the first hole MH may be blocked. In more detail, asillustrated in FIG. 3A, the charge control layer OL of which the endOL-E is exposed by the first hole MH does not extend to the second holeBR, but is cut. The second hole BR may separate a portion of the chargecontrol layer OL disposed between the first and second holes MH and BRfrom another portion of the charge control layer OL disposed outside thesecond hole BR. Thus, even though external moisture or oxygen isprovided through the first hole MH, the external moisture or oxygen maynot be transferred to the outside of the second hole BR. As a result, itis possible to stably prevent damage of the thin film element layer 20and/or the display element layer 30 existing outside the second hole BR.

In addition, according to an embodiment of the invention, the firstinorganic layer 32 and the second inorganic layer 34 may cover theportion between the first and second holes MH and BR, the inside of thesecond hole BR, and the outside of the second hole BR. In other words,the charge control layer OL and/or the first insulating layer 21, whichare adjacent to the second hole BR and are cut, may be covered by thefirst inorganic layer 32 and the second inorganic layer 34. Thus, theexternal moisture or oxygen may further be blocked.

FIG. 4 is a cross-sectional view illustrating a first barrier layer ofFIG. 2, according to an embodiment of the invention. FIG. 5 is a graphshowing characteristics of a laser transmitted through a first barrierlayer, according to an embodiment of the invention. FIG. 6 is across-sectional view illustrating a portion of the first barrier layerof FIG. 4, according to an embodiment of the invention.

Referring to FIG. 4, the first barrier layer 12 may include a pluralityof reflective layers INL1 to INLn. The reflective layers INL1 to INLnmay block or reflect laser light of a specific wavelength band. Here,the laser light of the specific wavelength band may be the laser lightof the second wavelength band which is used to form the second hole BRdescribed with reference to FIG. 2.

According to FIG. 5, for example, the laser light LS of the secondwavelength band may have a wavelength in a range from 300 nm to 400 nm.In the graph of FIG. 5, the horizontal axis represents a wavelength andthe vertical axis represents absorptance, reflectance, and transmittanceof light. The laser light LS may remove a portion of the second barrierlayer 14 and a portion of the second base layer 13 to form the secondhole BR overlapping with the peripheral area BA. In other words, thesecond barrier layer 14 and the second base layer 13 may have a highabsorptance for absorbing the laser light LS of the second wavelengthband. In an embodiment, the second barrier layer 14 according to theinvention may be formed of a single layer including the inorganicmaterial, and thus the transmittance and reflectance of the laser lightLS may be low in the second barrier layer 14.

In an embodiment, the first barrier layer 12 according to the inventionmay include the plurality of reflective layers INL1 to INLn. Thus, thefirst barrier layer 12 may have a low absorptance and a lowtransmittance of the laser light LS in the second wavelength band, butmay have a high reflectance of the laser light LS. Thus, the second holeBR may not be formed in the first barrier layer 12 by the laser lightLS. As a result, since moisture or oxygen permeating through the rearsurface of the first base layer 11 is blocked by the first barrier layer12, it is possible to prevent or substantially prevent the moisture oroxygen from permeating to the thin film element layer 20 and/or thedisplay element layer 30 through the second hole BR.

Referring again to FIG. 4, according to an embodiment of the invention,each of the reflective layers INL1 to INLn may include a first inorganicfilm and a second inorganic film, which have different refractiveindexes from each other and are stacked. In more detail, the firstbarrier layer 12 may include a plurality of the first inorganic filmsIO1 to IOn having a first refractive index and a plurality of the secondinorganic films IN1 to INn having a second refractive index. In anembodiment, the second inorganic films IN1 to INn and the firstinorganic films IO1 to IOn may be alternately stacked. In addition, atotal thickness of the first barrier layer 12 according to the inventionmay have a certain height H1, and, in an embodiment, the height H1 maybe in a range from 550 nm to 600 nm.

Four inorganic films IO1, IO2, IOn−1 and IOn of the first inorganicfilms IO1 to IOn and four inorganic films IN1, IN2, INn−1 and INn of thesecond inorganic films IN1 to INn are illustrated in FIG. 4 for thepurpose of ease and convenience in description and illustration.

In an embodiment, an uppermost film of the first barrier layer 12 may bean uppermost inorganic film IO1 of the first inorganic films IO1 to IOn,and a lowermost film of the first barrier layer 12 may be the lastinorganic film INn of the second inorganic films IN1 to INn.

In an embodiment, the first inorganic films IO1 to IOn may includesilicon oxide (SiOx). In an embodiment, the second inorganic films IN1to INn may include silicon nitride (SiNx). In an embodiment, the secondrefractive index of the second inorganic films IN1 to INn may be higherthan the first refractive index of the first inorganic films IO1 to IOn.

According to the above description, the first barrier layer 12 accordingto the invention may be provided as a distributed Bragg reflector havinga high reflectance. Since each of the reflective layers INL1 to INLnincludes the first inorganic film and the second inorganic film whichhave different refractive indexes from each other, the reflectance tothe external laser light may be increased.

In an embodiment, the first inorganic film is formed of silicon oxide(SiOx) and the second inorganic film is formed of silicon nitride(SiNx). However, embodiments of the invention are not limited thereto.In another embodiment, each of the first and second inorganic films mayinclude at least one of SiOx, SiNx, TiOx, AlOx, Al, or Ag. In stillanother embodiment, the first barrier layer 12 may be provided as ametal layer.

Referring to FIG. 6, at least two or more of the first inorganic filmsIO1 to IOn according to the invention may have different thicknessesfrom each other. For example, an uppermost first inorganic film IO1 mayhave a first height Ha and a next-uppermost first inorganic film IO2 mayhave a second height Hc. In an embodiment, the second height Hc of thenext-uppermost first inorganic film IO2 may be greater than the firstheight Ha of the uppermost first inorganic film IO1.

In addition, at least two or more of the second inorganic films IN1 toINn according to the invention may have different thicknesses from eachother. For example, an uppermost second inorganic film IN1 may have athird height Hb and a next-uppermost second inorganic film IN2 may havea fourth height Hd. In an embodiment, the fourth height Hd of thenext-uppermost second inorganic film IN2 may be less than the thirdheight Hb of the uppermost second inorganic film IN1.

In an embodiment, as illustrated in FIG. 6, the first height Ha may bedifferent from the third height Hb, and the second height Hc may bedifferent from the fourth height Hd. In other words, in an embodiment,the first inorganic films IO1 to IOn and the second inorganic films IN1to INn may have different thicknesses from each other.

FIGS. 7A to 7D are cross-sectional views illustrating a method ofmanufacturing a display panel, according to an embodiment of theinvention. FIG. 7E is an image showing a base substrate, according to anembodiment of the invention.

As illustrated in FIG. 7A, an untreated base substrate 10_I1 may beprovided. The untreated base substrate 10_I1 may include a firstuntreated base layer 11_I, a first untreated barrier layer 12_I, asecond untreated base layer 13_I, and a second untreated barrier layer14_I. The first untreated base layer 11_I and the second untreated baselayer 13_I may be stacked alternately with the first untreated barrierlayer 12_I and the second untreated barrier layer 14_I.

The first untreated base layer 11_I, the first untreated barrier layer12_I, the second untreated base layer 13_I, and the second untreatedbarrier layer 14_I may be sequentially stacked in an upward direction.The first untreated base layer 11_I may correspond to a lowermost layerof the untreated base substrate 10_I1, and the second untreated barrierlayer 14_I may correspond to an uppermost layer of the untreated basesubstrate 10_I1.

Thereafter, as illustrated in FIG. 7B, a cover layer MSL may be formedon the second untreated barrier layer 14_I. The cover layer MSL maycover the second untreated barrier layer 14_I.

The cover layer MSL may be formed using at least one of the thin filmelement layer 20 (see FIG. 2) and the display element layer 30 (see FIG.2), described above. For example, the cover layer MSL may be formedusing at least one of the first to fourth insulating layers 21, 22, 23,and 31 and the electrodes CE, IE, OE, and E1 (see FIG. 2).

A through-opening MSL-OP exposing at least a portion of the seconduntreated barrier layer 14_I may be formed in the cover layer MSL. In anembodiment, the through-opening MSL_OP of the cover layer MSL may beformed concurrently (e.g., simultaneously) in a process of forming atleast one of the first to fourth insulating layers 21, 22, 23, and 31and the electrodes CE, IE, OE, and E1. Thus, the cover layer MSL may beformed using an existing process without an additional process, and,thus, a process time and a process cost may be reduced.

Thereafter, as illustrated in FIG. 7C, laser light LS may be providedonto the cover layer MSL. The laser light LS may be laser light having awavelength band in a range from 300 nm to 400 nm. The laser light LS maybe light provided in an etching process. As illustrated in FIG. 7C, inan embodiment, the laser light LS may be provided in a radial form WV.Thus, each of the layers may be etched in a shape of which a widthbecomes wider toward a top thereof.

The first untreated base layer 11_I, the first untreated barrier layer12_I, the second untreated base layer 13_I, and the second untreatedbarrier layer 14_I of FIG. 7B may be changed into a first thermallytreated base layer 11_T, a first thermally treated barrier layer 12_T, asecond thermally treated base layer 13_T, and a second thermally treatedbarrier layer 14_T by the laser light LS, respectively.

In this case, the shapes of the second untreated base layer 13_I and thesecond untreated barrier layer 14_I may be different from those of thesecond thermally treated base layer 13_T and the second thermallytreated barrier layer 14_T. In other words, as illustrated in FIG. 7D, asecond hole BR_A may be formed in the second thermally treated baselayer 13_T and the second thermally treated barrier layer 14_T.

On the contrary, the shapes of the first untreated base layer 11_I andthe first untreated barrier layer 12_I may be the same or substantiallythe same as those of the first thermally treated base layer 11_T and thefirst thermally treated barrier layer 12_T. As illustrated in FIG. 7E,since the first barrier layer 12 reflects most of the laser light LS, ahole may not be formed in the first barrier layer 12 and the first baselayer 11 by the laser light LS.

In addition, as illustrated in FIG. 7D, an inner surface of the secondhole BR_A may have an undercut shape by a difference in absorptionbetween the layers with respect to the laser light LS, when viewed in across-sectional view. Like a region “BB,” the second thermally treatedbase layer 13_T may be undercut with respect to the second thermallytreated barrier layer 14_T. Thus, an inner surface of a first sub-holepenetrating the second thermally treated barrier layer 14_T maylaterally protrude from an inner surface of a second sub-hole defined inthe second thermally treated base layer 13_T.

FIG. 8 is a cross-sectional view illustrating a display panel of anelectronic device, according to another embodiment of the invention.

Referring to FIG. 8, a display panel 100-1 may further include a thirdhole BR2, as compared with the display panel 100 illustrated in FIG. 2.The other components of the display panel 100-1 of FIG. 8 may be thesame or substantially the same as corresponding components of thedisplay panel 100 illustrated in FIG. 2, and, thus, descriptions thereofwill be omitted.

In the present embodiment, the third hole BR2 recessed from the frontsurface of the base substrate 10 may further be defined in the basesubstrate 10. The third hole BR2 may be closer to a second hole BR1 thanto the first hole MH overlapping with the hole area HA, when viewed in aplan view. The second hole BR1 may surround the first hole MH and may bespaced apart from the first hole MH by a distance (e.g., a predetermineddistance), when viewed in a plan view. The third hole BR2 may surroundthe second hole BR1 and may be spaced apart from the second hole BR1 bya distance (e.g., a predetermined distance), when viewed in a plan view.

Structures of the second and third holes BR1 and BR2 may be the same orsubstantially the same as the structure of the second hole BRillustrated in FIG. 2. Thus, descriptions of the structures of thesecond and third holes BR1 and BR2 are omitted.

According to the above descriptions, moisture or oxygen permeatingthrough the first hole MH may be blocked by the second and third holesBR1 and BR2, and, thus, it is possible to effectively prevent themoisture or oxygen from being transferred to the thin film element layer20 and/or the display element layer 30.

According to the invention, it is possible to effectively prevent theelement from being damaged by moisture or oxygen permeating from theoutside. Thus, the reliability of the electronic device in amanufacturing process and in use may be improved.

In particular, it is possible to block moisture or oxygen permeatingthrough the rear surface of the base substrate of the display panel.

While the invention has been described with reference to some exampleembodiments, it will be apparent to those skilled in the art thatvarious changes and modifications may be made without departing from thespirit and scope of the invention. Therefore, it should be understoodthat the above embodiments are not limiting but, rather, areillustrative. Thus, the scope of the invention is to be determined bythe broadest permissible interpretation of the claims and theirequivalents, and shall not be restricted or limited by the foregoingdescription.

What is claimed is:
 1. A display panel comprising: a base substratewhich includes a front surface and a rear surface and in which athrough-portion and a first recessed-portion are defined, wherein thethrough-portion penetrates the front surface and the rear surface, andwherein the first recessed-portion is adjacent to the through-portion,and is recessed from the front surface; and a pixel layer on the frontsurface of the base substrate, wherein the base substrate comprises: afirst base layer including the rear surface of the base substrate; afirst barrier layer on the first base layer and comprising at least twoinorganic films with different refractive indexes; a second base layeron the first barrier layer; and a second barrier layer on the secondbase layer and including the front surface of the base substrate.
 2. Thedisplay panel of claim 1, wherein the first recessed-portion surroundsthe through-portion when viewed in a plan view.
 3. The display panel ofclaim 1, wherein the first recessed-portion is defined in the secondbase layer and the second barrier layer.
 4. The display panel of claim1, wherein the first recessed-portion is not defined in the first baselayer and the first barrier layer.
 5. The display panel of claim 1,wherein the at least two inorganic films have different thicknesses fromeach other.
 6. The display panel of claim 1, wherein a plurality ofsecond recessed-portions is further defined in the base substrate,wherein the second recessed-portions are closer to the firstrecessed-portion than to the through-portion, when viewed in a planview, and wherein the second recessed-portions are recessed from thefront surface of the base substrate.
 7. The display panel of claim 6,wherein the second recessed-portions surround the first recessed-portionin the plan view.
 8. The display panel of claim 6, wherein the secondrecessed-portions are not defined in the first base layer and the firstbarrier layer.
 9. The display panel of claim 1, wherein the firstbarrier layer includes first inorganic films having a first refractiveindex; and a plurality of second inorganic films having a secondrefractive index, wherein the first inorganic films and the secondinorganic films are alternately stacked.
 10. The display panel of claim9, wherein at least two or more of the first inorganic films havedifferent thicknesses from each other, and at least two or more of thesecond inorganic films have different thicknesses from each other. 11.The display panel of claim 9, wherein an uppermost film of the firstbarrier layer is one of the first inorganic films, and a lowermost filmof the first barrier layer is one of the second inorganic films, whereinthe second refractive index is higher than the first refractive index.12. The display panel of claim 1, wherein the first recessed-portion isdisposed between the through-portion and the pixel layer in a plan view.13. An electronic device comprising: a display panel comprising: a basesubstrate which includes a front surface and a rear surface and in whicha through-portion and a first recessed-portion are defined, wherein thethrough-portion penetrates the front surface and the rear surface, andwherein the first recessed-portion is recessed from the front surface;and an electronic module overlapping the through-portion, wherein thebase substrate comprises: a first base layer including the rear surfaceof the base substrate; a first barrier layer on the first base layer andcomprising at least two inorganic films with different refractiveindexes; a second base layer on the first barrier layer; and a secondbarrier layer on the second base layer and including the front surfaceof the base substrate.
 14. The electronic device of claim 13, whereinthe first recessed-portion has a closed loop shape surrounding thethrough-portion, when viewed in a plan view.
 15. The electronic deviceof claim 13, wherein the first recessed-portion is defined in the secondbase layer and the second barrier layer, wherein the firstrecessed-portion is not defined in the first base layer and the firstbarrier layer.
 16. The electronic device of claim 13, wherein aplurality of second recessed-portions is further defined in the basesubstrate, wherein the second recessed-portions are closer to the firstrecessed-portion than to the through-portion, when viewed in a planview, and wherein the second recessed-portions are recessed from thefront surface of the base substrate.
 17. The electronic device of claim13, wherein the electronic module overlaps with a display area of thedisplay panel.
 18. The electronic device of claim 17, wherein the firstrecessed-portion is disposed between the through-portion and a pixelarea included in the display area.